Galalith
/ˈɡaləlɪθ/Now chiefly historical
noun
A plastic made from casein by treatment with formaldehyde, often used as a substitute for tortoiseshell, horn, etc. Frequently attributive Compare casein plastic.
Origin
Early 20th century; earliest use found in The Trade Marks Journal. From German Galalith from ancient Greek γάλα milk + λίθος stone.